http://bugs.winehq.org/show_bug.cgi?id=27885
--- Comment #3 from Henri Verbeet hverbeet@gmail.com 2011-07-24 12:30:47 CDT --- The other part that's important for s3tc with r600g is the kernel. You need a fairly recent version, IIRC at least 2.6.39 (but you might as well go straight for 3.0). The GL format setup is done based on the table at http://source.winehq.org/git/wine.git/blob/04d541c26d4f50af2bf306dc11943bd12... Getting 0 for internal format pretty much means the required extension wasn't found, in this case that would be GL_EXT_texture_compression_s3tc. If you run with WINEDEBUG=+d3d_caps you'll probably see that it's not in the list of detected extensions in wined3d_adapter_init_gl_caps(). If this is due to the kernel being too old, it's probably not in your glxinfo output either.